Joints between pipes of different diameters and couplings and gaskets for the same

ABSTRACT

A joint between the ends of two pipes of different diameter formed by clamp-type segmental coupling elements having legs ending in key sections engaging grooves in the surfaces of the pipes. The leg for engagement with the pipe of smaller diameter is longer than the other leg. A pressure responsive gasket seated within the housing has lips engaging the pipe surfaces and has members for preventing the longer of the gasket legs from unseating its lip in response to pressure differential between the interior and exterior of the pipe. An additional rib may be provided for closing the space between the pipe ends.

United States Patent Young l [151 3,680,894 [451 Aug. 1,1972

[54] JOINTS BETWEEN PIPES OF DIFFERENT DIAMETERS AND COUPLINGS ANDGASKETS FOR THE SAME [72] Inventor: John S. Young, Berkeley Heights,

[73] Assignee: Victaulic Company of America,

South Plainfield, NJ.

[22] Filed: Oct. 30, 1970 i 21 Appl. No.: 85,616

[52] U.S. Cl. ..285/112, 277/206, 285/177, 285/367 [51] Int. Cl ..Fl6l 17/00 [58] Field of Search ..28/111, 367, 112, 177, 233; 277/206 [56]References Cited UNITED STATES PATENTS 1,701,326 2/1929 Johnson..285/112 X 1,899,695 2/1933 Johnson ..285/112X FOREIGN PATENTS ORAPPLICATIONS 92,964 6/ 1923 Austria ..285/1 12 323,252 12/1929 GreatBritain ..285/1 12 207,900 10/1966 Sweden...' ..285/112 PrimaryExaminer-Dave W. Arola Attorney-Albert M. Parker [5 7] ABSTRACT A jointbetween the ends of two pipes of different diameter formed by clamp-typesegmental coupling elements having legs ending inkey sections engaginggrooves in the surfaces of the pipes. The leg for engagement with thepipe of smallerdiameter is longer than the other leg. A pressureresponsive gasket seated within the housing has lips engaging the pipesurfaces and has members for preventing the longer of the gasket legsfrom unseating its lip in response to pressure differential between theinterior and exterior of the pipe. An additional rib may be provided forclosing the space between the pipe ends.

19 Claims, 15 Drawing Figures PATENTEDAUB 1 I972 sum 1 or 3 R6 1 N M V ATTORA/EY PATENTEBA 1 I973 SHEET 2 [IF 3 SHEET 3 OF 3 PATENTEDMIG 1 1972A TTOR/VEX JOINTS BETWEEN PIPES OF DIFFERENT DIAMETERS AND COUPLINGS ANDGASKETS FOR THE SAME BACKGROUND OF THE INVENTION 1. Field of theInvention The invention is in the field of readily applicable andremovable clamp-type couplings for effecting joints between the ends ofpipes. In particular, the invention is concerned with the making of suchjoints between pipes of different OD. and with the joints includingcoupling segments clamped together and providing key sections forreception in grooves in the outer surfaces of the pipe. Pressureresponsive gaskets are seated within the hollow of the couplings andhave lips engaging surfaces adjacent the ends of the pipes.

2. Description of the Prior Art Prior art efforts to make pressure tightjoints between ends of pipe of different O.D.s have usually involved theuse of threaded adapters or more complicated constructions. Thethreading of the pipes and applying of threaded adapter is timeconsuming, cannot be done unless the pipes are to be in exact alignment,and creates a rigid joint. Another common practice is to insert the pipeof smaller diameter part way into the pipe of larger diameter when thedimensions allow this and then join the two together by means of flangesor other elements permanently affixed to the pipes. This again is timeconsuming, expensive, and results in a rigid joint.

. I SUMMARY OF THE INVENTION The invention enables the quick couplingtogether of the ends of pipes of different diameters with couplingswhich are readily applied, creating joints which are strongly pressureresistant, whether the pressure be internal or external. The joints ofthe invention nevertheless allow a certain flexibility so thatvariations in pipe alignment to a moderate extent may be effected tosatisfy the particular service for which a pipeline is being laid. Thepipe ends do not overlap and are normally spaced a short distancelongitudinally.

The invention employs annular couplings formed of segments of cylinderswhich are formed with bases and radially inwardly extending side rimportions, terminating in ribs, known in the trade as key sections. Thepipes have key section receiving grooves formed into them through theirouter surfaces adjacent to, but spaced from, their ends. The rims are ofdifferent lengths with the longer one having its key section engagedwith the receiving groove in the pipe of smaller diameter. The set backof the grooves from the ends of the pipe provides for gasket lipreceiving surfaces between grooves and pipe ends. The pressureresponsive gaskets, housed within the channel formed by the base andrims of-the coupling, whose lips seat against the receiving surfaces onthe pipe, have hollow interiors so that pressure within the pipe forcesthe lips down against those surfaces.

Like the coupling housings, the gaskets have bases and radially inwardlyextending sides carrying the sealing lips, one of those sides beinglonger than the other. In the attempt to effect joints employing suchgaskets with fully hollow interiors, it was found that as the couplingsegments were tightened up to clamp them about the pipes the gasketswere distorted in such a way that the longer of the gasket sides movedlongitudinally on its seat toward the pipe end and became unseated tosufficient extent to be ineffective.

In accordance with the invention it was found that if a few spacedtransverse webs of the same material as, and preferably formedintegrally with, the gasket extended from the longer of the gasket sidespart way transversely across the hollow of the gasket without, however,engaging the shorter of the sides, this tendency of the longer side todistort so as to unseat its lip was overcome. One form of web was foundto be effective to prevent distortion of the side and unseating of thelip as the gasket was seated on the pipes when the pipes were subjectedto internal pressure only. Such web, however, did not supply thecharacteristics needed to keep the longer side from distorting so as tounseat its lip when the external pressure was greater than that withinthe pipes. A suitable web formation, however, was devised in accordancewith the invention to take care of both of these situations as will beapparent as the description of the invention proceeds.

Alternately, a gasket was devised having a median rib for extendingbetween and engaging the end faces of the pipes along with theadvantages of the pressure responsive gasket just referred to.

Thus, within a moderate pipe diameter differential the inventionprovides a fully effective, simple, economical joint whether somewhatflexible, or rigid, as desired that can be made between the ends ofpipes of different diameters. All that needs to be done to the pipes isto form standard grooves in their exterior surfaces. The gasket andcoupling segments are seated in place on the pipes and the segments,whether two or more, making up the complete annulus, are either boltedtogether or clamped together in some recognized manner.

BRIEF DESCRIPTION OF THE DRAWING In the accompanying drawing:

FIG. 1 is a plan view showing two sections of pipe of different diameterjointed together in alignment in accordance with the invention.

FIG. 2 is a similar view but showing the applicability of the inventionto the joining of pipes of the same and different diameters to a Tee.

FIG. 3 is a vertical enlarged section through the joint of FIG. 1.

FIG. 4 is an interior elevational view of a hemicylindrical couplinghousing element in accordance with the invention.

FIG. 5 is a side elevation viewing FIG. 4 from the right hand sidethereof with a part broken away and shown in section.

FIG. 6 is an interior half elevation of a gasket of one size inaccordance with the invention.

FIG. 6a is a similar view of a gasket of somewhat larger diameter.

FIG. 7 is a greatly enlarged transverse cross-sectional view of thegasket of FIG. 6, with the section taken just in advance of one of thegasket webs.

FIG. 7a is a cross-sectional view of a gasket having sides of differentextents but devoid of any internal web and illustrating the manner inwhich the lip at the end of the longer side is moved inward to unseatitself as the gasket is clamped and distorted within a coupling housmg.

FIG. 8 is a view similar to FIG. 7a showing the formation adopted by theinvention gasket of FIG. 7 when a coupling housing is clamped over thegasket to seat it in position at a pipe joint.

FIG. 9 is a view similar to FIG. 3 of a modified joint in accordancewith the invention employing a gasket carrying an intermediate rib.

FIG. is a view somewhat enlarged, but otherwise similar to FIGS. 6 and6a of the gasket employed in FIG. 9.

FIG. 11 is an enlarged transverse section of the gasket as shown in FIG.10 with the section taken just in advance of the webs.

FIG. 12 is a view similar to FIG. 7 showing a gasket with a somewhatdifferent form of web within it; and

FIG. 13 is an enlarged view similar to one-half of FIG. 3 where thegasket of FIG. 12 is employed in the making up of the joint.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In FIGS. 1 and 3 a joint inaccordance with the invention is illustrated as being made betweensections of pipe 1 and 20f differentdiameters. The pipes as here shownare of substantially the same wall thickness though the invention is. byno means limited in this regard. The only limitation is to thedifference in pipe O.D.s which should preferably not be greater than twoinches for effective coupling in accordance with the invention.

The sections of pipe 1 and 2 are shown as formed with external annulargrooves 3 and 4 concentric with the cylinder of the pipe. These groovesare seen to be spaced from the respective ends Sand 6 of the pipes byportions providing exterior surfaces 7 and 8 forming seats for thecoupling gaskets. Before going further it is to be noted that the pipeends 5 and 6 are spaced apart as shown at 9 which allows for flexibilityof the joint. In other words, for angular movement of the axis of one ofthe pipe sections with respect to the axis of the other. Thisflexibility in no way disturbs the pressure tight seal between the pipeends provided by the coupling of the invention. 8 I

The coupling member, generally indicated at 10, is here shown as beingformed of an annular base portion 1 1 from the sides of which rims l2and 13 extend radially inwardly and, as better shown in FIG. 4 providean inwardly opening channel 14 for the reception of a pressureresponsive gasket, generally indicated at 15. The preferred form of suchwhich is shown in various positions and portions in FIGS. 3, 6, 7 and 8.The gasket 15 has an annular base portion 16 from the edges of whichannular sides, or legs, 17 and 18 extend radially inwardly to terminatein generally laterally extending opposed lips 19 and 20.

As isapparent from the showings of the gasket 15 its side 17 is ofgreater extent than its side 18 in order to compensate for thedifierence in diameters between the pipes l and 2 with which the lips 19and 20 are to be engaged.

Referring now to FIG. 7, which shows the gasket 15 in its relaxed statebefore being clamped in a coupling housing for engagement with the endsurfaces of sections of pipes and to bridge the gap between the same,its lips 19 and 20 are inclined somewhat downwardly with respect to thecentral radical plane of the gasket.

them to seat effectively upon the pipe surface sections 7 and 8 providedtherefor.

The gasket 15 being formed of elastormeric material, normally a suitablesynthetic rubber, is relatively incompressible so the action in movingthe lips 19 and 20 from the open position as shown in FIG. 7 to theseated position asshown in FIGS. 3 and 8, is one of distorting theinitial shape of the material, causing it to flow into a different form,rather than a compressing of it.

The manner in which the flow of the material is brought about willbecome apparent by referring back to FIGS. 1 and 3 where the couplinghousing 10, usually of metal, is shown as being made up of two segmentsof a cylinder, one of which is shown per se in each of FIGS. 4 and 5 andwhich are shown as bolted together to form the complete cylinder bysuitable bolts 30 and 31. These bolts pass through bolt pads 32 and 33extending outwardly with respect to the cylindrical segments. The pads32 and 33 have specially formed, oval shaped, bolt receiving openings 34for reception of similarly shaped shanks on the bolts in order toprevent their rotation while nuts at the opposite ends thereof aretightened up. Also the size of the openings 34 with respect to the boltshanks permits sufficient swinging movement of the bolts to enable themto properly seat themselves. The bolt pads 33 and.34 also have radiallyextending surfaces 35 and 36 which come substantially together as theclamping is completed by the tightening of the bolts. I

In effecting a joint between pipe sections, such'as shown at 1 and 2 inFIG. 3, the pipe ends are brought in to the necessary proximity, andinto alignment, being slipped into the gasket 15 as this is done. Suchaction tends to materially move the lip surfaces 21 and 22 as shown inFIG. 7 up into the cylindrical position as shown at 23 and 24 in FIG. 8,but, at the outset, only moderately so inasmuch as the gaskets will nottake their final form until confined, in all directions. The next stepthen is to bring the coupling housing segments, commonly two in numberas shown at 37 and 38 in FIG. 3, into position over the gasket 15 whichis then received within the channel 14 .of the coupling housings. Thehousing segments would normally be first brought toward each other byhand and then as the key sections 39 and 40 carried by the housingrimsl2 and 13 respectively are aligned with their receiving grooves 3 and 4formed in the pipes, the nuts at the remote ends of the bolts 30 and 31are tightened until the opposed bolt pad surfaces 35 and 36 on thecoupling housing segments abut. The inside diameters of the couplingbeing somewhat larger than the pipe OD. and the groove, and the keysections 39 and 40 being somewhat narrower than the width of the grooves3 and 4, along with the fact that the gap 9 exists between the pipeends, allows the joint to be flexible. If a rigid joint is required, thepipe grooving configuration can be changed to achieve this end.

It will be apparent that as the clamping action of the coupling housingprogresses the gasket will be fully distorted by flow of its materialfrom the FIG. 7 position into the position shown in FIG. 3, and inenlarged cross-section form in FIG. 8. It was found, however,

that with a gasket having a completely hollow interior, as shown at 44in FIG. 7a, the closing action of the housing segments, due to the flowof material tend to swing the longer gasket side 17 inwardly so that itslip 19 moved at least part way off the seat provided for it on the pipe.Accordingly the gasket failed to maintain a tight joint against eitherpositive or negative pressure within the pipe. This was particularlytrue under negative pressure conditions.

To counteract the ineffective results achieved with a completely hollowgasket, as seen in FIG. 7a, and after considerable research work wasdone on the problem, diagonal webs were formed within the hollow of thegasket, as seen in FIGS. 12 and 13. The thickness, shape and spacing ofthe webs all had to be determined for effective results. As anon-limiting example it was determined that for a gasket to provide atight joint between pipe sections of approximately 6% and 5% OD.diagonal spaced webs integral with the gasket of one-quarter inch inthickness and at a spacing of 30 would be sufficient to overcome thetendency of the leg 17 to move inwardly as shown in FIG. 7a. To do this,however, it was found to be essential for the diagonal border of thewebs to commence at the top of the radius 46 where the upper surface ofthe lip 19 joins the interior of the side 17 and to extend to andterminate at the position 47 where the curve 48 commences its extentfrom the interior of the base 16 of the gasket and extends around to topof the lip 20. Thus the webs meet the criteria of not interfering withthe action of either sealing lip and remaining clear of the end 6 of thelarger diameter pipe 2 as seen in FIG. 13.

The gasket with such a series of webs as in FIGS. 12 and 13 worksadmirably to overcome the condition illustrated in FIG. 7a and tomaintain the longer side 17 and lip 19 of the gasket in position to makea tight joint as against positive pressure within the joined pipes. Itwas rather surprisingly found, however, that when the interior of thepipes was subjected to negative pressure the diagonal edge webs 45became ineffective and the gasket again failed in the manner illustratedin FIG. 7a. However, such gasket has utility when used to seal againstpositive pressure in the pipe so to a worthwhile extent it solves atleast part of the problem encountered in the use of gaskets entirelydevoid of webs.

The preferred form of the invention, found to satisfy all conditions ofassembly, positive and negative pressure, involves a new relationshipbetween gasket and other features of the construction. The details ofthis are variously shown in FIGS. 3, 6, 6a, 7 and 8. The basic gasketconstruction, as already described, has a base 16 and sides 12 and 13but in this instance a plurality of rectangular webs 50 formedintegrally with the gasket extend from the inner surfaces of the side 17and base 16 part way across the hollow 44 of the gasket. Hence theborders of the web rectangle are the sides 51 and 52 joined respectivelyto the gasket side 17 and base 16,- and the two free sides, 53,54extending at substantially right angles with respect to the side 17 andbase 16. Like the diagonal edge web 45 previously described, however,the webs 50 are so proportioned and positioned that they do notinterfere with the movement of the lips 19 and 20 as the bottom surfacesof those lips 21 and 22 are moved into the positions 23 and 24, (FIG.8), in the tightening of the gasket in place within the couplinghousings. Thus the bottom free edge 53 of the web 50 commences at theposition 55 where the radius at the top surface of the lip 19 joins theinner surface of the side 17 while the side free edge 54 of the web 50meets the inner surface of the base 16 at the position 56 where thecurved interior of the side 18 meets the inner surface of the base 16 ina substantially flat portion. Thus it is apparent that the spaced webs'50 will in no way interfere with the movement of the elastomericmaterial of the sides 17 and 18 or of their lips 19 and 20 from theposition of FIG. 7 to that of FIGS.8 and 3. Likewise such webs will inno way in'- terfere with the reaction of those lips to internal pressurewithin the pipe acting upon them.

The thickness and spacing of the webs 50 is important since too thick aweb can cause rippling at the sealing lip while, if the web is not thickenough, it will tend to buckle rather than assist in the positioning ofthe longside 17 of the gasket against the interior of the housing and ofits lip 19 against the pipe end as needed for proper sealing. As anexample, it has been found that in a gasket for use in sealing the jointbetween standard pipes having O.D.s of approximately 6.5 inches andapproximately 5.5 inches the transverse webs 50 should be approximatelyone-quarter of an inch thick and should be spaced at 30 about theinterior circumference of the gasket. Moderate variations from thesefactors may be adopted as will be apparent to those skilled in the artdependent on such factors as the size and hardness of the gasket.

For properly controlling the action of the gasket for use in joiningpipes of larger O.D.s the webs 50 could be somewhat smaller angle so asto effect the same gasket side control. An-illustration of this is seenin the larger gasket shown in FIG.6a where parts similar to those ingasket of FIG. 6 are given the same reference characters but with thesufiix a. Here the showing is of a greater number of webs 50a since theyare spaced at 25 apart instead of the 30 spacing of the webs of FIG. 6.In this way a thickening of the webs is hardly needed but may beeffected if desired and if considerations, such as variation in gaskethardness, call for it.

The provision of the rectangular webs 50 and their cooperation with theend 6 of the larger pipe 2 solve all the problems of gasket seating andmaintenance of gasket effectiveness whether subject to positive ornegative pressure. In the first place, the provision of the webs aloneserves to prevent unseatingof the lip 19 as the material of the gasketis caused to flow while the coupling housings are clamped in place overthe gaskets and their key sections are seated within the pipe groove.Secondly, and even more importantly, the web 50 prevents inward movementof the side 17 and unseating of the lip 19 in response to externalpressure greater than that within the pipe. This is accomplished by thewebs 50 being formed, as best seen in FIG. 3, to extend far enoughacross the hollow of the gasket so that the free vertical sides 54 ofthe webs come just into engagement with the end face 6 of the pipesection 2 as the joint is completed. This backing up of the webssupplies the resistance needed to protect the long side 17 of the gasketfrom being moved inward by the action of external pressure. Inwardsliding of the lips 19 and consequent unseating of them laterally isprevented. Nevertheless the gasket hollow 44 is substantially maintainedso that the lips 19 and 20 will respond to internal pressure and sealtightly against the pipe.

It is thus seen that the simple coupling of pipe sections of differentdiameters by the use of clamp type couplings to provide a tight seal atthe joint, whether the pressure to be sealed against is external orinternal, is fully provided by the invention.

An alternative form of gasket for use in effecting joints between pipesof different diameters is illustrated in FIGS. 9, 10, and 1 1. Here likeparts to those in FIGS. 3-8 are given like reference characters, so theonly additional description needs to be that of the parts changed andadded. In particular, the gasket here shown has an intermediate radiallyinwardly extending center leg 60 having a width between its sides 61 and62 the same as, or slightly greater than, the distance between the endfaces 5 and 6 of the pipes 1 and 2 when the coupling housings have beenbrought home. This center leg 60 serves to close off the gap between thepipe ends but is needed more from the standpoint of smoothing out thefluid flow at the point where the diameter of the fluid path changes,than from the standpoint of sealing thejoint. Such sealing is alreadyeffectively done by the action of the basic gasket of C- shaped crosssection.

Smoothing out of the flow path is brought about particularly by theradiused nose 63 on the leg 60. In the first place, the extent of theleg is such that its innermost edge 64' aligns with the inner surface 65of the pipe 1 (FIG. 9). From there the convex curve 63 extends outwardlyin such a manner as to meet the straight side 61 of the leg at theposition 66 where the leg 60 initially comes into contact with the innersurface 67 of the pipe section 2. Since the leg 60 and its curved endsurface 63 are circumferential, a smooth, rounded transition surface isprovided for the flow of fluid past the joint regardless of thedirection of that flow.

In this instance there is a series of gasket webs 70 which extendintegrally between the side wall 17 of the gasket and its center leg 60,bridging the space therebetween from the base 16 of the gaskets down toa bottom edge 71. This bottom edge 71 lies just above the position wherethe rounded to surface of the lip 19 merges with the inner side wallsurface of the side wall 17 again leaving the lip 19 entirely free toperform its sealing function. Also the end face 6 of the pipe backs upthe leg 60 in alignment with the lower portion of the web 70 as bestseen in FIG. 9. Hence, as in FIGS. 3, 6 and 8 protection isprovidedagainst displacement of the leg 17 and the lip 19 as a result ofexternal pressure on the joint.

FIG. 2 merely illustrates the application of the joints in accordancewith the invention to a situation where a Tee, generally indicated at75, has three pipe sections 76, 77 and 78 joined thereto. A joint 79 inaccordance with the invention is effected by means of grooves andcouplings as heretofore described where the pipe 76 is of one diameterand the Tee at this position is of the greater diameter. As shown at theother end of the Tee the pipe section 77 is of the same diameter as theadjacent end of the Tee 75, so a standard coupling with rims and gasketsides of the same length is all that is needed. The pipe 78, however,joined at the center of the Tee 75 by the coupling 80 has a greaterdiameter than the adjacent portion 81 of the Tee, so the reversesituation to the joint between the section 76 and the Tee is present.Heretofore threaded reducers would have been needed to make the jointssuch as '79 and 80 with consequent greater expense of construction partpreparation and application while eliminating the possibility offlexiblity at the joints.

It will be apparent to those skilled in this art that this invention canbe practiced through various modifications other than the preferred andmodified forms disclosed herein illustrative of the invention and theapplicability of the same to the coupling of pipes of differentdiameters in a simple and economical manner. It is accordingly to beunderstood that since certain changes may be made in the parts andassemblies above disclosed without departing from the spirit or scope ofthe invention all matter contained in the above description or shown inthe accompanying drawing shall be interpreted as illustrative and not ina binding sense.

Having described my invention what I claim as new and desire to secureby Letters Patent is:

l. A gasket for sealing the joint between aligned sections of pipe ofdifferent diameters, said gasket comprising a short cylinder C-shaped incross section having a base portion and having side portions extendingradially inwardly from said base portion at the longitudinal endsthereof forming a hollow within said gasket, one of said side portionshaving a greater radial extent than the other thereof, said sidesterminating in oppositely inwardly extending lips and a plurality ofthin transversely extending uniformly spaced webs within the hollow ofsaid gasket, said webs extending integrally from the innersurface of thelonger of said sides and the inner face of said base, all said websbeing free from engagement with the shorter of said sides.

2. A gasket as in claim 1, said webs commencing at a position closelyadjacent to but above the juncture of said longer side and the lipcarried thereby and terminating at a position closely adjacent to butspaced inwardly from the position where said shorter side joins saidbase.

3. A gasket as in claim 1, said webs being of rectangular shape.

4. A gasket as in claim 3, said webs extending radially inwardly beyondthe lip carried by the shorter of said sides.

5. A gasket as in claim 2, the outer edge of said gasket being on adiagonal line extending from said commencing position to saidterminating position.

6. A gasket as in claim 1 and including a radially inwardly extendingleg extending from the base of said gasket intermediate said sides, saidwebs terminating at the side of said leg opposite said longer side.

7. A gasket as in claim 6, said leg terminating in a convexly roundedface on the side thereof opposite said shorter side.

8. In clamp type couplings for forming a joint between pipes ofdifferent diameters, segmental coupling housings formed to make acomplete cylinder when applied to pipes to be joined, each of saidhousing segments having a base portion and having radially inwardlyextending rims at each side of said base portion, said rims forming withthe interior of said base portion a gasket receiving channel, one ofsaid rims having a greater radial extent than the other, the radial endfaces of said rims being formed with key sections for engagement withgrooves formed in the pipes to be joined, and a pressure responsivegasket formed for mated reception in said receiving channel, said gaskethaving a circumferential base portion and radially extending sideportions extending therefrom forming a hollow therewithin, said sideportions terminating in inwardly extending opposed lips for engagementwith the surfaces of pipes to be joined, one of said side portionshaving a greater radial dimension than the other thereof incorrespondence with the rim of greater radial extent, and transverselyextending thin webs at spaced positions within the hollow of saidgasket, said webs extending integrally from and connecting the innersurface of the longer of said sides with the inner surface of the baseof said gasket, all said webs being free from engagement with theshorter of said side portions.

9. In couplings as in claim 8, said gasket webs extending from thelonger of said sides at a position spaced above the lip carried by thesame and continuing in spaced relationship with respect to said sideportion of shorter radial extent.

10. In couplings as in claim 9, said gasket webs being rectangular incross section, having a bottom edge substantially parallel to said baseand a free side edge substantially parallel to the longer of said sides.

11. In couplings as in claim 8, said gasket including a radiallyinwardly extending leg positioned intermediate said sides and extending,when said gasket is confined by said housing, to a position radiallyinwardly of the key section of said rim of greater radial extent.

12. In couplings as in claim 11, said webs extending to and terminatingat said leg.

13. In couplings as in claim 8, said webs having a free edge extendingdiagonally between the longer of said sides and the inner surface ofsaid base.

14. A joint between pipes of different diameters which comprises, a pairof pipe sections positioned end to end, one having a greater diameterthan the other, the end face of the larger diameter pipe being exposedradially outwardly of the end of the smaller diameter pipe, each of saidpipe sections being formed with circumferential grooves thereinadjacent, but spaced from, the end faces thereof leaving gasket engagingsurfaces on the exteriors of said pipes between said grooves and saidend faces, clamp type couplings surrounding said pipes, said couplingsbeing generally C shaped in cross section, having a base portion withradially inwardly extending rims at the ends thereof, said rimsterminating in key sections formed for reception in said pipe grooves,the rim at one longitudinal end of said coupling having a greater radialextent than the other of said rims for engagement of the key sectioncarried by the same within the groove of the smaller diametered one ofsaid pipes, a pressure responsive gasket generally C shaped in crosssection received within-said C shaped coupling housing, said gaskethaving a base portion with radially inwardly extending sides at the endsthereof providing a hollow therewithin, one of said sides of said gasketbeing longer than the other thereof, oppositely inwardly extending lipscarried at the inner ends of said sides with the lip on the longer ofsaid sides engaging the gasket surface of said i e of s aller diameter,transverse] extending web n ie ns wit l iin said hollow of said gaskeipositioned at uniformly spaced intervals around the circumference ofsaid gasket, said web means being integrally secured to the inner faceof the longer of said sides and the inner face of the base of saidgasket, said webs serving to resist movement of said longer side towardsaid shorter side, all of said webs being free from engagement with saidshorter side of said gasket.

15. A joint as in claim 14, said webs having an edge portion engagedwith the end face of said larger diameter pipe.

16. A joint as in claim 14, said webs being rectangular in crosssection, extending radially inwardly with respect to the lip carried bythe shorter of said gasket sides, and having an edge face ofsaidradially inwardly extending portion of said webs engaging said endface of said pipe of greater dimension.

17. A joint as in claim 14, said gasket including a radiallyinwardlyextending leg, said leg extending into, filling the space between, andengaging the end faces of said pipe sections terminating at the innersurface of the smaller of said pipe sections.

18. A joint as in claim 17, the face of said leg extending from theinner surface of the larger of said pipes to the inner surface of thesmaller of said pipes being on a convex curve.

19. A joint as in claim 17, said webs extending between said longer sideof said gasket and the opposed face of said leg and extending radiallyto a position opposite the end face of said pipe section of largerdiameter.

1. A gasket for sealing the joint between aligned sections of pipe of different diameters, said gasket comprising a short cylinder C-shaped in cross section having a base portion and having side portions extending radially inwardly from said base portion at the longitudinal ends thereof forming a hollow within said gasket, one of said side portions having a greater radial extent than the other thereof, said sides terminating in oppositely inwardly extending lips and a plurality of thin transversely extending uniformly spaced webs within the hollow of said gasket, said webs extending integrally from the inner surface of the longer of said sides and the inner face of said base, all said webs being free from engagement with the shorter of said sides.
 2. A gasket as in claim 1, said webs commencing at a position closely adjacent to but above the juncture of said longer side and the lip carried thereby and terminating at a position closely adjacent to but spaced inwardly from the position where said shorter side joins said base.
 3. A gasket as in claim 1, said webs being of rectangular shape.
 4. A gasket as in claim 3, said webs extending radially inwardly beyond the lip carried by the shorter of said sides.
 5. A gasket as in claim 2, the outer edge of said gasket being on a diagonal line extending from said commencing position to said terminating position.
 6. A gasket as in claim 1 and including a radially inwardly extending leg extending from the base of said gasket intermediate said sides, said webs terminating at the side of said leg opposite said longer side.
 7. A gasket as in claim 6, said leg terminating in a convexly rounded face on the side thereof opposite said shorter side.
 8. In clamp type couplings for forming a joint between pipes of different diameters, segmental coupling housings formed to make a complete cylinder when applied to pipes to be joined, each of said housing segments Having a base portion and having radially inwardly extending rims at each side of said base portion, said rims forming with the interior of said base portion a gasket receiving channel, one of said rims having a greater radial extent than the other, the radial end faces of said rims being formed with key sections for engagement with grooves formed in the pipes to be joined, and a pressure responsive gasket formed for mated reception in said receiving channel, said gasket having a circumferential base portion and radially extending side portions extending therefrom forming a hollow therewithin, said side portions terminating in inwardly extending opposed lips for engagement with the surfaces of pipes to be joined, one of said side portions having a greater radial dimension than the other thereof in correspondence with the rim of greater radial extent, and transversely extending thin webs at spaced positions within the hollow of said gasket, said webs extending integrally from and connecting the inner surface of the longer of said sides with the inner surface of the base of said gasket, all said webs being free from engagement with the shorter of said side portions.
 9. In couplings as in claim 8, said gasket webs extending from the longer of said sides at a position spaced above the lip carried by the same and continuing in spaced relationship with respect to said side portion of shorter radial extent.
 10. In couplings as in claim 9, said gasket webs being rectangular in cross section, having a bottom edge substantially parallel to said base and a free side edge substantially parallel to the longer of said sides.
 11. In couplings as in claim 8, said gasket including a radially inwardly extending leg positioned intermediate said sides and extending, when said gasket is confined by said housing, to a position radially inwardly of the key section of said rim of greater radial extent.
 12. In couplings as in claim 11, said webs extending to and terminating at said leg.
 13. In couplings as in claim 8, said webs having a free edge extending diagonally between the longer of said sides and the inner surface of said base.
 14. A joint between pipes of different diameters which comprises, a pair of pipe sections positioned end to end, one having a greater diameter than the other, the end face of the larger diameter pipe being exposed radially outwardly of the end of the smaller diameter pipe, each of said pipe sections being formed with circumferential grooves therein adjacent, but spaced from, the end faces thereof leaving gasket engaging surfaces on the exteriors of said pipes between said grooves and said end faces, clamp type couplings surrounding said pipes, said couplings being generally C shaped in cross section, having a base portion with radially inwardly extending rims at the ends thereof, said rims terminating in key sections formed for reception in said pipe grooves, the rim at one longitudinal end of said coupling having a greater radial extent than the other of said rims for engagement of the key section carried by the same within the groove of the smaller diametered one of said pipes, a pressure responsive gasket generally C shaped in cross section received within said C shaped coupling housing, said gasket having a base portion with radially inwardly extending sides at the ends thereof providing a hollow therewithin, one of said sides of said gasket being longer than the other thereof, oppositely inwardly extending lips carried at the inner ends of said sides with the lip on the longer of said sides engaging the gasket surface of said pipe of smaller diameter, transversely extending web means within said hollow of said gasket positioned at uniformly spaced intervals around the circumference of said gasket, said web means being integrally secured to the inner face of the longer of said sides and the inner face of the base of said gasket, said webs serving to resist movement of said longer side toward said shorter side, all of said webs being free froM engagement with said shorter side of said gasket.
 15. A joint as in claim 14, said webs having an edge portion engaged with the end face of said larger diameter pipe.
 16. A joint as in claim 14, said webs being rectangular in cross section, extending radially inwardly with respect to the lip carried by the shorter of said gasket sides, and having an edge face of said radially inwardly extending portion of said webs engaging said end face of said pipe of greater dimension.
 17. A joint as in claim 14, said gasket including a radially inwardly extending leg, said leg extending into, filling the space between, and engaging the end faces of said pipe sections terminating at the inner surface of the smaller of said pipe sections.
 18. A joint as in claim 17, the face of said leg extending from the inner surface of the larger of said pipes to the inner surface of the smaller of said pipes being on a convex curve.
 19. A joint as in claim 17, said webs extending between said longer side of said gasket and the opposed face of said leg and extending radially to a position opposite the end face of said pipe section of larger diameter. 